The properties of 1.55 mum up-conversion single-photon detector are analyzed using the differential-phase-shift keying (DPSK) protocol. We compare the error rate and the communication rate as a function of distance for three quantum key distribution QKD protocols: the Bennett-Brassard 1984, the Bennett-Brassard-Mermin 1992, and the DPSK. We show that the significant advantage of the up-conversion detector than the commonly used InGaAs/InP avalanche photodiode (APD), and the properties of QKD can be greatly improved by using this detector. View full abstract»

In this paper, we introduce a compact measuring system, to analyze microstructure force property. The system is specially designed in which a mechanical test machine, a PCB board based on an USB connection for device driving and data collection, and processing software were contained. This system can be used for measuring deformation characteristics of MEMS structures by bending method. To confirm the feasibility of the system, an experiment was performed on a micro pillar. View full abstract»

According to the needs in such fields as IC manufacturing and ultra-precision machining, a precision positioning system based on macro-micro dual-drive was developed. The macro positioning system is a two dimensional high-speed large-scale precision positioning system based on linear motor drive. The micro positioning system is a low speed ultra-precision positioning system based on the PZT and flexure hinge. The two systems are combined in order to achieve high-speed large-scale ultra-precision position. To the advance of our research, we have done some experimental research on the macro positioning system. The experiment results show that the macro positioning system can position at micron accuracy in the large workspace of 300 mm times 300 mm under the condition of design load. Square of the carrying platform is 250 mm times 250 mm. The positioning accuracy is less than 3 mum and the maximum velocity of this system can reach 500 mm/s. View full abstract»

A newly designed three-degree-of-freedom compliant parallel micromanipulator (CPM) with partially decoupled characteristics of XYZ translational motion is proposed in this paper. The CPM is driven by the selected piezoelectric actuators (PZTs) whose strokes are amplified by using the amplification lever mechanism. The design procedure of the CPM is presented in detail, and the CPM parasitic motion is studied analytically. Moreover, its motion properties are verified through the finite element analysis conducted with ANSYS software package. The simulation results reveal that the CPM has negligible parasitic rotations and negligible parasitic translation along one direction, and it possesses a good decoupled property. The CPM is expected to be applied to operate the objects in micro/nano-meter scales with high precision. View full abstract»

A multi-layer structural inertia micro-switch with conjoined snake springs has been designed based on non-silicon substrate. The micro-switch consists mainly of a suspended thick proof mass as a movable electrode, and an elastic beam with holes as a fixed electrode that is some distance above the proof mass. This conformation benefits the protection of the switch against severe shock damage. The relationship between threshold acceleration and proof mass thickness H of the micro-switch has been investigated by theoretical analysis and finite element simulation. It is suggested that the micro-switch with H=50mum generally fulfils the expected 50g threshold. The dynamic contact simulation of the micro-switch has been implemented under the half-sine wave shock with 50g peak value, and its response time is about 0.22ms. View full abstract»

Cell docking is a very important technique in on-chip cell-based research. In previous studies, different kinds of microdam structures have been used for cell docking. However, they brought extra flowing resistance and induced the jam of microfluidic channel. Furthermore, they were too complex for fabricating. Thus, they could not be widely used. In this study, a large number of magnetic beads were patterned within microchannel to form microscale dam structure, which could be used for cell docking and cell-based research. This magnetic beads based dam structure could be fabricated on packaged chips. It could also be constructed or removed by turning on or turning off extrinsic magnetic fields. This cell-docking method is of significant advantage than previous methods, and it may become an important tool in future cell lab-on-a-chip research. View full abstract»

A novel method for fabricating Cu-based carbon nanofiber (CNF) composite film as contact electrode of MEMS electromagnetic relay is presented in this paper. All the electroplating equipments and electroplating solution including CNFs are all placed in ultrasonic agitation environment during the whole electroplating process to avoid the agglomerating of CNFs on the surface of the MEMS contactor. The tested results shows that CNFs were distributed evenly and few spheric Cu- based CNF particles were discovered. The composition of the electroplating solution is optimized by many experiments. When the concentration of the CNFs is up to the 4g/L, the maximum hardness (208 HV) of Cu-based CNF composite film is achieved with the improvement of 50.9% compared with the one of the pure copper. When the MEMS contactor with Cu-based CNF composite film is applied in an electromagnetic microrelay, the contact resistance is reduced to 200~300m . View full abstract»

In this work magnetic particles are synthesized by in situ formation of magnetite in the gel phase through coprecipitation of Fe(II) and Fe(III) in alkaline media. Preparation parameters of Fe3O4 nanoparticles are full tested by orthogonal test. The study is devoted to synthesis and characterization of the structure and properties of Fe3O4 nanoparticles and magnetic field sensitive polymer gels composed of cross-linked PVA and magnetite. The structure and properties of magnetic field sensitive polymer gels and Fe3O4 nanoparticles are studied by X-ray diffraction (XRD), transmission electronmicroscopy (TEM), vibration sample magnetometery (VSM), electron microscope (EM) and infrared (IR).The ability of this magneto-elastic magnetic field sensitive polymer gels to deflect in the presence of a magnetic field was explored in this study. The dependence of deflection on the iron oxide concentration and magnetic field strength was also investigated. Finally, one approach on how to make a soft finger of robot were discussed. View full abstract»

Robustness performance is one of the most important concerns in the design of ESD (electro-static discharge) protection devices, and this quality plays a more and more important role in NEMS protection devices. Improvement of robustness requires not only experience but also TCAD (technology computer aided design) methodology to evaluate ESD protection devices in NEMS. A novel TCAD methodology for robustness evaluation is presented and developed here. This methodology is based on mix-mode transient circuit simulation, and this simulation method depicts ESD events better. Through analyse of the time effect on power accumulation, an important key parameter, named as robustness coefficient, is provided to characterize and evaluate robustness performance of ESD protection devices quantificationally. Based on analyse of this robustness coefficient of different ESD devices under different ESD models and levels, the results show that this TCAD methodology has a good ability of convergence, and can be used to evaluate robustness performance of ESD protection devices objectively. View full abstract»

The atomic force microscope system has become a popular and useful instrument to measure the intermolecular forces with atomic-resolution that can be applied in electronics, biological analysis, materials, semiconductors etc. This paper studies the complex nonlinear dynamic behavior of the probe tip between the sample and cantilever of an atomic force microscope using the differential transformation method (DTM). The dynamic behavior of the probe tip is characterized by reference to bifurcation diagrams, and Poincare maps produced using the time-series data obtained from differential transformation method. The results indicate that the probe tip behavior is significantly dependent on the magnitude of the vibrational amplitude. Specifically, the probe tip motion changes from T- periodic to 3T-periodic, then from 6T-periodic to multi-periodic, and finally to chaotic motion with windows of periodic motion as the vibrational amplitude is increased from 0 to 5.0. Furthermore, it is demonstrated that the differential transformation method is in good agreement for the considered system. View full abstract»

The hetero-junction source and drain of SOI MAG-MOSFET of n-type nano-polycrystalline silicon films on p-type crystalline silicon were fabricated and the Hall effect was studies. The nano-polycrystalline silicon films was deposited in a plasma enhanced chemical vapor deposition system. Experiments shown, the nano-polycrystalline silicon films-Si hetero-source and hetero-drain are abrupt hetero-junction and shown good temperature stability and good rectifying properties. The SOI MAG-MOSFET is devices made on very thin silicon layers on top of the insulating oxide. The advantages of using SOI structures are that the parasitic capacitance can be significantly reduced as well as some unique properties of SOI that allow low- power and low-voltage operations to be improved. Appeal of a structure like this the possibility of application that would require the flexibility of nano-polycrystalline silicon films. View full abstract»

How to identify the frequency-velocity model of micro robot mobile in liquid which was driven by intelligent material was studied in this paper. The sample data set that reflected the relationship between the vibrating frequency of driving flanks and moving velocity of micro robot was obtained by experiments. After comparing the of regression support vector machine (R- SVM) with the least square support vector machine (LS-SVM), this paper selected the latter method to identify the model. Then the LS-SVM was trained and testified by the sample data set and contrast experiments had been done. The primary testing result shows that the identified model is accurate if the training information is enough. The general performance testing result shows that the identified model reflects the nonlinear mapping relationship between the flanks driven frequency and moving velocity of robot even though the setting frequency is out of range of sample data set. The dynamic performance result shows that the identified model is not only quite accurate during the positive step period but also precise during the negative step period . The study is the important basic to control the micro robot mobile in liquid. View full abstract»

This paper aims at designing a kind of advanced micro-force sensor that can measure force in the range of sub- micro-Newton (muN). To accurately measure the micro interactive force (for example, adhesion, surface tension, friction, and assembly force) acting on micro devices during micromanipulation, the polyvinylidene fluoride (PVDF) is fabricated highly sensitive force sensors. This paper illustrates the modeling method of a PVDF sensor. The transformation between the micro interactive force and the output of the sensor is described. To calibrate the transformation, the model of the PVDF cantilever beam that shows the relationship between the interactive force and the deflection of the sensor probe tip is built first. Then, by given deflection, the interactive force can be calculated with the model. Finally, the transformation can be calibrated. Experiment results verify the effectiveness and accuracy of the transformation model, and the sub-muN sensitivity of the sensor. This micro force sensing technology will solve an important problem that restricts the development of micromanipulation and batch assembly of micro devices. View full abstract»

In order to improve the complicated fabrication process and integration of 3D micromixers, we propose a novel planar self-stirring micromixer with high mixing efficiency and low pressure drop. The planar micromixer with vortices agitation for mixing enhancement had been successfully investigated by the Taguchi method, CFD-ACE simulations and experiments. The factor sensitivity test was performed by L9(34) orthogonal array in Taguchi method. Degree of sensitivity ranks as: Gap ratio > Number of mixing units > Baffle width > Chamber ratio. At Re = 20, micromixer shows 93% mixing efficiency in the adaptive design with three mixing units, H/W = 1/8, Wm/W = 1 and Wm = 80. The corresponding pressure drop of this adaptive design is only 4600 Pa at Re 20. Much improved mixing is obtained experimentally in this adaptive design at Re 20. The results of the factor sensitivity test can provide useful information for the design of the micromixers with obstacles. Merits of this design are easy fabrication and high integration capability. View full abstract»

This paper develops a rapid algorithm to extract the Young's modulus and residual stress of structural material of capacitive micro-device from measuring the pre-pull-in capacitance variation of the micro test beam made of the material to be tested. The extracted Young's modului and residual stresses of demonstrated samples agree very well with the experimental measurement. The present method is expected to be applicable to the wafer-level testing in micro-device manufacture and compatible with the wafer-level testing in IC industry since the test and pick-up signals are both electrical. View full abstract»

Silicon microchannel plates have been explored intensively for numerous applications especially for weak light detection and night vision. The electrochemical etching in hydrofluoric acid-based solutions is known as a technique for porous silicon formation. This paper presents a new process for the formation of microchannel structure and the separation of the Si MCP from p-type starting substrates by a single-step electrochemical etching in HF-based electrolytes. High aspect ratio microchannels are fabricated by electrochemical etching and the conditions under which the undercut occurs are investigated. The formation of the undercut is found to be primarily determined by both current density and HF concentration, which determine the MCP structure thickness as well. View full abstract»

Silicon microchannel structures exhibit numerous possible applications. In this report, the oxidation of high area ratio silicon microchannels used in weak light detection and night vision is studied. High area ratio microchannels are fabricated by electrochemical etching, and the influences of oxidation time and environments on the microstructures are investigated and analyzed combined with computer simulation. Damages and distortion are found after the oxidation process. It is found that after oxidation at high temperature, surface morphology becomes rough and followed polishing step is recommended to smooth the silicon microchannels' surfaces. View full abstract»

We report measurements and numerical modeling of nanopillars transistor in consisting of a multilayer SiNx/Si/SiNx structure and an electrical side gate for single-electron tunnel and Coulomb modulation at room temperature. The device has an ultrasmall quantum box of ~ 10 times 10 times 10 nm3 and its manufacture is fully VLSI processing compatible. Finite-element analysis shows that the maximum deformation is ~ 3 Aring and the corresponding elastic energy stored is ~ 50 meV. The vibration frequency calculated is ~ 1012 Hz in consistent with interference measurement. The current induced ranging from 1 pA to 0.1 pA is also consistent with experimental data, thus confirming that single-electron tunnel indeed can generate mechanical vibrations. View full abstract»